Mixing apparatus



p 1965 K. H. SCHIPPERS ETAL 3,206,170

. MIXING APPARATUS 2 Sheets-Sheet 1 Filed April 6, 1962 FIG. 1

INVENTORS. KARL HEINZ SCHIPPERS ROBERT SLUIJTERS AT OR Y Sept. 14, 1965 K. H. SCHIPPERS ETAL 3,206,179

MIXING APPARATUS Filed April 6, 1962 2 Sheets-Sheet 2 FIG. 6

BACK FRONT BACK FRONT BACK FRONT BACK FRONT i-ZBE igg BACK FRONT INVENTORS.

- TT NEY United States Patent 3,206,170 MIXING APPARATUS Karl Heinz Schippers, Remscheirl-Leunep, Germany, and Robert Sluijters, Arnhem, Netherlands, assignors to American Enka Corporation, Enka, N.C., a corporation of Delaware Filed Apr. 6, 1962, Ser. No. 185,539 Claims priority, application lgetherlands, Apr. 12, 1961,

63, 34 7 Claims. (Cl. 259-4) This invention relates generally to apparatus for mixing liquids and more particularly to liquid mixing apparatus in which there are no moving parts.

Liquid mixers having no moving parts are known. Generally they comprise a mixing chamber provided with partitions or guide members to successively divide and re-unite the stream of flowing liquid. Their advantage over mixers with moving parts is that the mixing operation is carried out entirely within an absolutely liquidtight space, and they require no driving means and considerably less mixing energy. Recent improvements therein, such as those disclosed in US. patent applications Serial No. 774,305, filed November 17, 1958, now Patent No. 3,051,452 and Serial No. 821,917, filed June 22, 1959, now Patent No. 3,051,453, now make it possible to mix liquids as thoroughly as was formerly possible using mixers having moving parts. Mixers employing these improvements are constructed so that the stream of liquid passes through guide members or partitions which divide the stream of liquid into partial streams, deformed and displaced relative to one another, and then re-unite them to form one stream of liquid. The successive splitting of the main stream is carried out in such manner that the resulting streams contain liquid that is obtained from as many as possible of the previously formed partial streams.

In order to obtain satisfactory mixing results with the above system, a very complex disposition of the guide members is required. This leads to construction problems, particularly a design which will provide a proper arrangement of the guide members and at the same time be simple enough that the mixer is relatively inexpensive to build. Moreover, the mixer must be precisionally built so that it can be kept liquid-tight, especially if it is used to mix or homogenize highly viscous liquids under high pressure and at temperatures of several hundred degrees Centigrade.

Accordingly, it is an object of this invention to provide a liquid mixer without moving parts that does not have the disadvantages inherent in the prior art mixers.

Another object of this invention is to provide a liquid mixer without moving parts that is simple and inexpensive to construct.

Still another object of this invention is to provide a simply constructed liquid mixer without moving parts that can be built with such precision that it is liquid tight even at high pressures and temperatures.

These and other objects will become apparent from the following detailed description.

The invention comprises constructing a mixer in which the guide members all consist of pairs of identical plates or disks through which run two or more substantially axially directed chanenls that widen from one face of the disk to the other. The disks are so adjoined in series that faces having identical channel cross-sections oppose each other with the wide channel cross-sections being disposed at right angles to one another.

The disks may be made of various materials depending on the liquid to be mixed. Porcelain or glass disks should be used if corrosive liquids are to be mixed. When the mixing is to be carried out under high pressures and temperatures it is preferred to use steel disks. The disks are preferably arranged in pairs, each pair consisting of identical disks, the order of which is reversed in each succeeding pair.

Mixers constructed according to the invention are inexpensive and simple to mass produce. They may be manufactured by forging, ramming, pressing, or casting. Also, they can be made using various cutting operations. This last-mentioned process is particularly suitable if steel disks of high precision are required. Moreover, another advantage of the mixer is that the mixing action can be improved to an unlimited extent simply by increasing the number of pairs of disks.

The channels in the disks must be shaped such that the resistance to flow is as low as possible and at the same time, enable manufacture of the disks to be as simple as possible. These requirements are satisfied by providing bored channels or smooth straight-surfaced channelwalls.

In principle there is no limit to the number of channels per disk. However, it is preferred to provide each disk with only two channels. The disk is thus simpler to construct and the resistance to flow is reduced. Formation of dead pockets inside the mixer can be avoided if the narrowest channel cross-sections have a common axis of symmetry.

The disks may be cemented or welded to each other to ensure that they are liquid tight. If, however, the faces of the disks are sufficiently smooth and parallel, it has been found simpler to clamp the disks together. This can be done, for example, by placing a bored flange at each end of the series of disks and clamping the disks together by tightening bolts inside the flanges. A preferred construction is to arrange a series of the disks inside a tightly fitting tube. The disks may then simply be clamped between end plates secured to the tube.

An embodiment of the invention which is particularly suitable for mixing a stream of liquid with the lowest possible increase in pressure comprises positioning between the adjacent faces having expanded channel cross sections a spacing disk provided with a hole such that it commutes with both of the two expanded channel crosssections in each disk. It has been found that where the channel walls of disks provided with two channels are flat surfaces, the walls of each channel being for the greater part parallel to the disk axis and for the remaining part inclined relative thereto, the mixer will provide optimum mixing action if the thickness of a spacing disk is equal to 1-cos on S111 ct times the diameter of the narrowest cross-section of the channel. The angle between the disk axis and the oblique channel wall is represented by a. The spacing disks may also be constructed such that the hole therein is smaller than the sum of the expanded channel cross-section of the main disks, as a result of which the stream is slightly narrowed. This permits the pressure to be adjusted and adapted to various operating conditions. Under some circumstances, it also improves the mixing action.

Preferably, the disks have two substantially axial channels which expand from one face to the other in an amount approximately twice the smallest cross-sectional area. The channel cross-sections may be circular at one face and expand into an approximately elliptical shape, or it may be square, or approximately square in shape and expand into a rectangle. Since the latter embodiment is simplier to manufacture, it is preferred, particularly if only two channels are provided. When the channels are square and expand to rectangles three walls of each channel are placed parallel to the disk axis and the fourth wall is arranged oblique relative to the disk axis. A diagonal drawn through the two square crosssections of the channel at one face of the disk preferably forms a straight line intersecting the disk axis.

For a better understanding of the invention, the following description is given in conjunction with the accompanying drawings wherein:

FIGURE 1 shows an assembled mixer in longitudinal V FIGURES 2a, 2b, and 2c represent a single disk mixing member, vi wed res ectiyelgrrom thefront, in sec tion along line AA in FIGURE 2; uidfror'rl the rear.

FIGURE 3 shows two adjoining disk mixing members.

FIGURE 4 shows an embodiment of a disk; mixing member.

FIGURE 5 shows two disk mixing members provided with a spacing disk.

FIGURE 6 shows front and back faces of a series of disks as they are arranged in the mixer together with a schematic illustration of how the stream of liquid is divided and mixed in passing through the channels.

In FIGURE 1, the numeral 1 refers to a tube, at the ends of which two flanges 2 and 3 are mounted. The rim of each flange is provided with holes 4 for securing the liquid mixer to the other equipment. In flange 2 there is an o ening 5 which, left to right, changes from a round into a square cross-section having the same area. Flange 3 is positioned around tuber, so that the entrance thereof is clear, making it possible for the narrow portion of the detachable flange 6 to be slid into the tube 1.-

In flange '6, there are provided holes 7 located such that they are in line with holes 4 iii flange Betwe n the holes 7 in flange 6, there are equisp'aeed thread holes 8 located in line with holes 9 bored in flange 3. Prior to mounting the mixer the flanges 3 and 6 are drawn together provisionally by means of screws 10. When securing the mounted mixer to its supply and discharge systems (not shown) the flanges 3 and 6 are also drawn together by screws through the holes 4 and 7. Opening 11 in flange 6 is the mirror-image of opening 5 in flange 2. Clamped between flanges 2 and 6 are a number of disk-shaped mixing members 12 to 16, inclusive, which are held in their correct relative positions by pins 17. The FIGURES 2a, 2b, and 2c show how through each of the disks there run two channels 18 and 19. In the face of the disk shown in the left view, FIGURE 2a, channels 18 and 19 open as two squares with their diagonals in a direct line with each other. The right view, FIGURE 2c, or opposite face of the disk shows that the two channels are widened to two rectangles, which together form a square. The side of this square is twice the side of each of the squares 18 and 19.

FIGURE 2b represents a cross-section taken along line A-A in FIGURE 2c. The channels 18 and 19 have four flat walls, three of which run parallel to the disk axis. The other wall, 20 in channel 19, and 21 in channel 18, is inclined relative to the disk axis.

FIGURE 3 shows how two disk mixing members 22 and 23 are joined. The figure is a cross-section taken along a plane slightly off the center line of the disks. The two mixing members are identical and have their two square channel openings 18 and 19 joined in direct line with each other. Succeeding pairs of disks in the mixer are joined in a line in the same relative positions.

FIGURE 4 shows a different embodiment of a disk mixing member wherein the oblique walls in the channels do not pass entirely from one face to the other. Under some circumstances this embodiment has been found to be more suitable for accurate mass production.

FIGURE 5 shows disk mixing members 22 and 23 in a diiferent order, with a spacing disk 25 positioned between them. The disk 25 is provided with a square channel whose cross-section corresponds to the square crosssection formed from the combined rectangular outlet openings of the channels 18 and 19. The thickness of the disk 25 is so chosen that the distance S is equal to the side of the square openings of the channels 18 and 19.. It has been found that in this manner optimum mixing: action can be obtained. Thus, the thickness of disk 25' is correct if the total thickness of one of the disks 22 or 23, plus disk 25 is equal to the length of the oblique channel wall in the disk mixing members.

FIGURE 6 depicts schematically from left to right and top to bottom a series of six disks, 26, 27, 28, 29, 30, 31, arranged in pairs as they are typically placed in a mixer cylinder. Back and front faces of each disk are shown in the manner in which they adjoin each other. The lined portions within the two channels illustrate how the mixing action is accomplished by successively dividing and reuniting the flowing liquid stream.

The apparatus of this invention has been found to be particularly suitable for use in the manufacture of tubes and rods from thermosplastic material. It is also suitable for use in the melt spinning of threads or films. Different embodiments of the apparatus may be used for widely varying purposes and for processing an infinite number of liquids.

While the invention has been described in connection with the foregoing drawings, many changes, modifications and embodiments within the scope of the invention will be apparent to those skilled in the art. Accordingly, it is intended that the invention be limited only as set forth in the following claims.

What is claimed is:

1. A blending apparatus comprising a first plate and. at least one identical additional plate, each plate having a front face, a back face and two orifices extending therebet-ween, the orifices in the front face having in cross sec-- tion substantially equal major and minor axes, the orifices in the back face having parallel major axes at least tit is the length of the minor axes, and means securing said plates with the back face adjoining and with the major axes of one back face extending at right angles to the major axes of the cooperating back face.

2. A liquid mixing apparatus comprising a series of identical plates each having at least two axially directed channels which widen laterally from one face of the plate to the other, the cross sections of each channel at one plate face having equal major and minor axes and at the other plate face having major axes at least twice the minor axis, the minor axis at both faces being substantially equal, the major axes of each channel disposed parallel to each other, said plates arranged with the plate faces having identical channel cross sections adjoining each other and the major axis of the widened channel cross sections at right angles, whereby a stream of unmixed materials passing through said channels is divided and reunited to effect thorough mixing.

3. A liquid mixing apparatus comprising an inlet port for supplying unmixed materials to be blended, an outlet port for drawing off said material after blending, and a series of identical plates positioned between said ports, each plate having at least two axially directed channels passing therethrough which widen laterally from one face of the plate to the other, the cross sections of each channel at one plate face having equal major and minor axes and at the other plate face having major axes at least twice the minor axes, the said minor axes at both faces being substantially equal, the major axes of each channel disposed generally parallel to each other, said plates joined in series with the plate faces having identical channel cross sections adjoining each other and with the major axes of the widened channel cross sections at right angles, whereby a stream of unmixed materials passing through said channels is successively divided and reunited to effect thorough mixing.

4. The apparatus of claim 3 in which the channels widen from a square cross section on one face'of the plate to a rectangular cross section on the other face.

5. A liquid mixing apparatus comprising an inlet port for introducing unmixed materials to be blended, an outlet port for discharging said mateirals after blending and a series of identical discs positioned between said ports, each of said discs having at least two axially directed channels passing therethrough which widen laterally from one face of the disc to the other, the narrowest channel cross sections of said discs having a common axis of asymmetry, the cross sections of each channel at one plate face having equal major and minor axes and at the other plate face having major axes at least twice the minor axes, the said minor axes at both faces being subtsantially equal, the major axes of each channel disposed substantially parallel to each other, said plates joined in series with the plate faces having identical channel cross sections adjoining each other and with the major axes of the widened channel cross sections at right angles, such that the channels in each disc communicate with the channels in the succeeding disc and alternately cross whereby a stream of unmixed materials passing through said channels is successively divided and reunited to effect thorough mixing.

6. The apparatus of claim 5 in which spacing disks are placed between said disk faces having widened channel cross-sections, said spacing disks being provided with one channel large enough to commute with both of the widened channel cross-sections on the face of each of said disks.

7. The apparatus of claim 5 in which the disk channels widen from a square shape cross-section on one face of the disk to a rectangular cross-section on the other face.

References Cited by the Examiner UNITED STATES PATENTS 1,915,867 6/33 Penick 13842 2,085,132 6/37 Underwood 259--4 2,740,616 4/56 Walden 2594 3,051,453 8/62 Sluijters 259-4 3,182,965 5/65 Sluijters 2594 FOREIGN PATENTS 3 50,716 6/ 31 Great Britain.

CHARLES A. WILLMUTH, Primary Examiner. 

1. A BLENDING APPARATUS COMPRISING, A FIRST PLATE AND AT LEAST ONE IDENTICAL ADDITIONAL PLATE, EACH PLATE HAVING A FRONT FACE, A BACK FACE AND TWO ORIFICES EXTENDING THEREBETWEEN, THE ORIFICES IN THE FRONT FACE HAVING IN CROSS SECTION SUBSTANTIALLY EQUAL MAJOR AND MINOR AXES, THE ORIFICES IN THE BACK FACE HAVING PARALLEL MAJOR AXES AT LEAST TWICE THE LENGTH OF THE MINOR AXES, AND MEANS SECURING SAID PLATES WITH THE BACK FACE ADJOINING AND WITH THE MAJOR AXES OF ONE BACK FACE EXTENDING AT RIGHT ANGLES TO THE MAJOR AXES OF THE COOPERATING BACK FACE. 